Telephonic signaling apparatus



G. H. BLISS. Telephone-Signaling Apparatus,

No. 223,469. Patented Jan 13,1880.

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UNITED STATES ATENT OFFICE;

GEORGE E. BLISS, OF PITTSFIELD, MASSACHUSETTS.

TELEPHONIC SIGNALING APPARATUS.

SPECIFICATION forming part of Letters Patent No. 223,469, dated January 13, 1880. Application filed August 25, 1879.

, scription, in connection with the accompanying drawings, is a specification.

My invention relates to a method of operating telephone-calls; and it consists in an armature-controlling device operated by a clock or time-train to render the signal-bell of each telephone of a circuit inoperative except at a certain moment, the moment or exact time for operating each signal-bell in the circuit being different at each telephone in the circuit, and being known at the central oflice, so that by breaking the circuit from the central office at the proper moment the signal for any telephone or instrument in a circuit may be operated Without disturbing any other signal in the circuit, thereby obviating the now disagreeable sounding in each ofiice occupied by a tele phone and watching for a certain number of strokes of the bell to indicate that office.

The invention also consists in means for antomatically regulating the movement or correctin g the time of the different clocks or timetrains in the circuit and keeping them in unison with a central clock for each circuit located at the central office.

In this present embodiment of my invention 1 have shown the hammer of the usual signalbell, operated in the usual manner by an electro-magnet, as provided with an arm or lever suitably weighted to counterbalance the hammer of the bell and hold it from falling back when the circuit is broken, thereby preventing the hammer striking the bell and giving a signal, as it would otherwise do when the circuit was again closed, in the usual manner of giving signals.

I also provide suitable connections between the weight and a time-train or clock-move ment, to raise the said Weight and hold it elevated for a suitable time, usually about four seconds, at suitable intervals-say once a minute--during which time, and at no other time, the signal, when the weight is so lifted, may be sounded, as usual.

The times for operating each signal are different for the different telephones in the same circuit-as, for instance, a telephone, A, may have its signal operative between five and nine telephone B may be operative between ten and fourteen seconds, andso on, this allowing ten telephones for each circuit, and permitting the signal of each telephone to be operated at least once in a minute, such division of time allowing time to signal the central ofiice without interfering with the other signalsof the circuit, and to regulate the clocks or tiine'trains of the circuit which drive the armature-controlling devices, as will be hereinafter described.

As herein shown, the weight for holding the armature forward is attached to a suspending work or one of the usual arbors of the clock, and provided near its middle portion with a lug situated above and adapted to be operated by the armature-controllin g device, set in motion or rotation by one of the arbors of the clock, preferably that carrying the secondhand, it consequently rotating the said device once a minute.

This armature-controlling device is herein shown as a disk provided with a cam or projection and attached to a second-hand arbor, the said cam or projection at every revolution striking the lug on the lever, raising the said lever and its connected suspending-rod, to lift the weight and leave the bell-hammer free to respond to the electro-magnet if the current is then broken from the central oifice. The said cam or projection is sufficiently broad to hold up the lever and weight for the proper interval, and its face should be inclined so as to allow the lever and weight to sink gradually when closing the armature against the electromagnet, so as not to ring the bell in case the circuit happens to be open. These cams are placed in a different position in each clock connected with each of the different telephones of the circuit, so that the time for operating the signals of each telephone shall be different.

In order to keep the clocks in unison, or so that the second-hand points to the same figure in all the clocks of each telephone-circuit, 1 provide an automatic clock or time-train stop,

which at suitable intervals, herein shown as seconds after each minute, while a signal of rod connected at its upper end with one end of a bar, pivoted at its other end to the frame- 'once an hour, (but it may easily be more or less than one hour,) stops all the clocks of each circuit with the second-hands at 0, after which all the clocks of the circuit are automatically started from the central clock when the clock at the central station comesto the 0-point.

Thus by regulating the speed of all the clocks of each circuit by the usual regulators so that they run nearly accurately, but atrifle fast, they may be all held back at the end of each hour for asecond, or any fraction thereof, which they may have gained, thereby enabling all the clocks of a circuit, by the usual regulators, to be kept so as never to vary a whole second, which is near enough for practical operation.

This operation of correcting the clocks and securing unison of time and movement may be accomplished in the following manner: The cam-disk before mentioned has a second pin or projection so located thereon that when the second-hand is at 0 it is in proper position to be engaged by a catch'on a bar pivoted beneath the cam, the said pivoted bar being so connected with the bell-hammer by a second link or cord and arm, similar to that before described in connection with the weight, that its catch can only engage the pin of the cam whenthe bell-hammer is back-that is, when both the weight is lifted and the circuit is open, which two conditions are brought about once an hour (or at other required intervals) in the following manner: The cam-projection is so arranged that by its action alone the weight before described is never lifted at the proper moment to permit the stop-catch to act; but a wire is attached to the weight-lifting arm in proper position to engage a rod connected with the hour-hand arbor at the proper moment to hold the weight-arm up for a short interval of time after it has been raised by the said cam-projection, thus leaving the bellhammer free to fall back when the circuit is opened, which is automatically done, about three seconds before the second-hand arrives at 0, by a switch connected with the central clock at the central office, thus leaving the stop-catches in all the clocks of the circuit free to engage and stop the said clocks with their second-hands at 0 til], at the proper moment,.the clock at the central office automatically closes the circuit and rings the signalbells, and by the connections frees the stop-catches and starts the clocks all in unison.

This method of keeping clocks in unison may be of use in other than telephonic circuits, and I do not wish to confine it to that particular use.

Figure 1 shows a front view of a telephone signal-bell and attached clock provided with my improvement, the usual clock-dial being omitted; but such dial is shown in another figure; Fig. 2, a rear side elevation of the clock at the central office, with its devices for making and breaking the current to start the clock in circuit with it; Figs. 3 and 4, details of Fi 2; Fig. 5, the dial removed from Fig. 1; and Fig. 6, a detail showing the lever which is acted upon by the armature-controlling device to lift the weight at the proper time and release the armature, with the armature-controlliu g device in front edge view.

The bell a, the electro-magnet b, with its armature c, and connected bell-hammer c, pivoted at d, and in circuit, are common to tele phone-signals, and need not therefore be further described.

The armature c has attached to it a leverarm, (1 adapted to be acted upon by a weight, 6, of sufficient amount to hold the hammer 0 against the bell when the circuit is open and the armatureis not attracted by the magnet, the said weight 0 being connected by a suspeuding-rod,f, with one end of the lifting-arm g pivoted at its other end to the arbor g, or to the frame h of the clock-work, which is of any usual construction.

The lifting-arm g is provided near its middle with a lug. h, to engage the cam-projection 6 on the cam-disk j, which controls the armature, the cam-disk turning on the same arbor and in unison with the second-hand k, so that the said lifting-arm in each clock is raised once a minute and lifts the weight 6, thereby leaving the-armature 0 and bell-hammer 0 free to act. This cam-proj ection is of sufficient width to retain the weight elevated for a suitable number of seconds, and is inclined, as at 2, (see Fig. 6,) to allow the weight to fall back gradually, so as not to. give a signal if the circuit happens to be open. These camprojections are at different positions on the different clocks of the circuit. The one shown in the drawings is arranged to operate when the second-hand is at 50. A table' is kept at the central office showing the operating time of each telephone in the circuit.

To call the telephone shown in the drawings the operator at the central office would break and close the circuit a few times just. when the second-hand of the central clock was at 50, at which moment the signal-bell connected with the clock shown in the drawings, and that bell alone of all thebells in the circuit, would sound. A certain number of seconds will be reserved by the cam-disk for signaling the main office.

Between the points 56 and O cams or projections are omitted from all the armaturecontrolling devices of the circuit, as this time or space is required once an hour, or at other required intervals, forcorrectin g the clocks in the circuit, which is done by the following mechanism: The cam-disk j has a second pin or projection, (4. so placed as not to interfere with the lifting-arm y, it being, however, in proper position to be engaged when the second-hand is at 0 by the catch 1 on the stop-arm m, pivoted at 3 and counterbalanced at one end, as at 4, so as to raise the catch into position to engage the said pin a. The other end of the stop-arm is connected by a link, m with a lever-arm, n, similar to the one, 0?, which holds the weight 0. This arrangement permits the catch on the stop-arm to rise onlywhen the bell-hammer is back-that is, when both the IIO weight 6 is raised and the circuit open-a combination of circumstances which is brought about in the following manner: The liftingarm is provided with a wire, suitably formed to be held up bythe end of an L-shaped rod, 0, attached to the hour-hand arbor and rotating therewith, the L portion of which is of a length to be passed over in just one minute, and is turned away from the end of the wire 0 The L-shaped rod is elastic, and bears against the end of the Wire 0? just before it is raised by the cam i, when the end of the L- shaped arm slips under the wire 0 and holds it and the connected arm 9 and Weight 0 up for the space of a minute, thus leaving the bell-hammer free to fall back upon the openin g of the circuit, which is accomplished, when the central clock second-hand is about at 58, by a switch, which may be as shown in Figs. 2 to at. In this switch the wire 5 is shown connected with one wire of the circuit, and is twisted, as at 6, to form a spring, by which its free end contacts with one fork of the U shaped portion 7, connected with the other wire of the circuit. Just at the proper time an arm, 8, rotated by the centralclock,G, bearsagainst the wire 5, moving it toward the other fork of the U-shaped wire, and when it is between the two forks the circuit is broken, allowing the catches to stop the clocks, and then, by a further movement, the said wire touches the other arm of the fork and again closes the circuit, thereby, through suitable connections, as described, simultaneously starting all the clocks of the circuit with their second-hands in like positions.

The bell may be rendered inoperative except at the proper time by means of a damper operated in a similar manner to the weight 6.

The instruments or means employed to determine the intervals for sounding signals and for correcting the time of and starting the clocks may be such as to make said intervals of longer or shorter duration, as described.

An essential feature of my system is to arrange the bell of the signal apparatus and the hammer and its operating parts so that the bells at the different offices of the circuit in which they are placed shall not operate or be capable of being operated at the same time.

1 do not broadly claim sounding an alarm or signal by clock-work alone or by electricity.

In the drawings I have shown the clock and signal of but one telephone-station; but it will be understood that similar parts are placed in the room occupied by each telephone of the circuit, the cam-wheels 9', however, having their projections 11 differently located.-

In Fig. l the L-shaped arm has acted upon the wire 0 and lifted the lever g and weight, and the lever mhas been raised to engage projection a and the clock is stopped, ready to be released by the switch or.current-breaker shown in Figs. 2 to 4.

I claim-- 1. A clock or time-train and an armaturecontrolling device driven thereby, combined with a bell or other signal, ahammer or striker therefor, and an electro-magnet, and connecting devices between the armature-controlling device and armature, to hold the armature against the eleetro-magnet at all times except atthe exact time indicated by the armaturecoutrolling device, to thereby permit the said signal to be sounded only at predetermined intervals of time, to avoid sounding more than one bell or signal in each circuit at one time, substantially as described.

2. In a telephonic circuit, a series of clocks or time-trains and bells operated by electromagnets, the armatures of which are adapted to be released by a break in the electric current, combined with a series of armature-controlling devices, each one of which in all the clocks or time-trains of the circuit is adapted to release the armature of its own electro-magnet at a different time from any of the others, whereby any signal in connection with any telephone of the circuit may be called at a predetermined and definite time, and at no other time, at which time all the other armatures which operate all the other bells of the circuit are mechanically and positively held closed, to thereby permit but one signal for one telephone of the circuit to be sounded at the same time, substantially as described.

3. A time-train or clock. to operate an armature-controlling device in a telephonic circuit and automatically release an armature at stated intervals, to permit it at that time, and only atthat time, to be operated by a break of the battery-current, combined with a check or stop to temporarily arrest the motion of the clock or time-train at regular intervals of time, to permit each clock or time train in the telephonic circuit to be stopped at regular intervals of time preparatory to being again started all together, to insure uniformity of time or speed of movement of the armature-releasing devices of all the clocks of the circuit, substantially as described.

4:. A time-train or clock to operate an armature-controllin g device in a telephonic circuit and automatically release an armature at stated intervals, to permit it at the proper time, and only at that time, to be operated by a break of the battery-current, combined with a check or stop to temporarily arrest the motion of the clock or time-train at regular intervals of time, to permit each clock or timetrain in the telephonic circuit to be stopped at regular intervals, and with a central clock in electric connection with all the other clocks of the circuit, and circuit-breaking devices or switch operated by the said central clock, whereby the clock or clocks in circuit with the central clock may be automatically started at the same defined time, as and for the purpose set forth.

5. In combination, one of the main arbors of a clock, an arm and connections to raise the weight which holds the armature closed a certain number of seconds, at regular intervals, When the said Weight is raised to release the armatnre and permit it to be operated by the battery-currel'lt, if desired, the bell or signal being noiseless at all other times, substantially as described.

In testimony whereof I have signed my 20 name to this specification in the presence of two subscribing witnesses.

GEORGE H. BLISS. Witnesses:

G. W. GREGORY, N. E. WHITNEY. 

